JP6532681B2 - Chair - Google Patents

Description

  The present invention relates to a chair.

  There is disclosed a chair provided with a backrest frame rising from the back of a seat and a backboard supported by the front of the backrest frame (e.g., Patent Document 1). In this chair, a pair of left and right engaging portions, which are cylindrical bodies in the vertical direction at least the lower surface of which is open on the back surface of the back plate, is integrally protruded backward, and the backrest frame The pair of left and right locking portions provided on the upper and lower sides are engaged with each other so as to be relatively rotatable around the vertical axis.

JP 2012-176276 A

  One of the functions required of the chair is a hold feeling that wraps the back of the seated person and the waist. For example, according to Patent Document 1 described above, it is considered that a hold feeling can be obtained such that a seated person is encased from the left and right sides. However, for example, in the technique described in Patent Document 1, it is assumed that the back plate does not sufficiently follow the posture of the seated person depending on the posture of the seated person, for example, when the seated person takes a twisting posture. Ru. In this case, the seated person can not be held sufficiently.

  An object of the present invention is to provide a technique related to a chair capable of holding the back and the waist of a seated person irrespective of the posture of the seated person in view of the above problems.

  In the present invention, in order to solve the problems described above, the back plate and the backrest frame are engaged so as to allow deflection of the backboard due to the load when seated, and the height and back of the seated person near the waist In the vicinity of both ends in the width direction of the plate, an engagement portion of the waist that allows relative movement between the back plate and the backrest frame is provided around the waist rotation axis extending in the vertical direction, above the engagement portion of the waist And, inside the width direction both ends of the backplate, it decided to provide the upper engagement part which permits relative movement of the backplate and the backrest frame around the upper rotation axis which extends to the top and bottom direction .

  In detail, the chair according to the present invention includes a seat body, a back plate provided behind the seat body and bent by a load when seated, and located behind the back plate to support the back plate. A backrest frame, and an engaging portion connected to the backrest frame to engage the backboard and the backrest frame so as to allow deflection of the backboard due to a load when seated. The engaging portion is positioned near the waist of the seat occupant's waist and near both end portions in the width direction of the back plate, and relative to the back plate and the backrest frame about the waist rotation axis extending vertically. Engaging portion for allowing a proper movement, and above the engaging portion of the waist and inside the both end portions in the width direction of the back plate, around an upper rotation axis extending in the vertical direction, An upper portion that allows relative movement between the back plate and the backrest frame And a engaging portion.

In the chair according to the present invention, the relative movement between the back plate and the backrest frame is permitted around the waist rotation axis extending in the vertical direction by providing the engagement portion of the waist. Therefore, the waist portion of the back plate is flexibly bent, and the back plate can easily come into contact with the seated person's waist. For example, even when the seated person takes forward or backward inclination, the backboard follows the seated person's waist and the backboard easily comes into contact with the seated person's waist, so the waistline of the seated person is always held can do. Further, in the chair according to the present invention, by providing the upper engaging portion, the back plate follows the back of the seated person even if the posture is changed as well as the waist, and the back plate easily hits the seated person's back Therefore, the seated person can always hold his / her back.

  In addition, for example, when the seated person takes a twisting posture (for example, a posture in which a large amount of load is applied to one side) or the like, it is assumed that the amount of displacement of the spine located above the waist increases. Ru. In the chair according to the present invention, the upper engaging portion has a width of the back plate so that the back plate can follow the movement of the back where the displacement amount is expected to be larger than the waist when the seated person changes the posture. It is located inside the both ends of the direction. If the upper engaging portions are positioned at both ends in the width direction of the back plate, the back plate can not be deformed outside the upper engaging portions. On the other hand, the back plate can be deformed to the outside of the upper engaging portion by positioning the upper engaging portion inside the both end portions in the width direction of the back plate. That is, according to the chair which concerns on this invention, the freedom degree of a deformation | transformation of a back board, in other words, the followability of a back board can be improved more. Therefore, regardless of the posture of the seated person, it is possible to hold the seated person's back and waist. In addition, about the engaging part of a waist part, it is assumed that the displacement amount at the time of a seated person changing an attitude | position is smaller than a back. Therefore, it is preferable that the engagement portion of the waist portion be positioned at either end in the width direction of the back plate or inside near the both ends.

  Here, the upper engaging portion may allow relative movement between the back plate and the backrest frame around the upper rotation axis and in the up-down direction. This further improves the freedom of relative movement between the back plate and the backrest frame. As a result, the freedom of deformation of the backboard supported by the backrest frame can be further improved.

  In addition, at least one of the engagement portion of the waist and the engagement portion of the upper portion has a biasing portion that biases the back plate bent by a load when seated. Good. This makes it easier for the back plate to follow the waist and back of the seated person, particularly when the seated person returns the posture, and can further hold the waist and back of the seated person.

  Further, the engagement portion of the waist portion includes a waist rotation shaft extending in the vertical direction, and a waist bearing through which the waist rotation shaft passes, and the upper engagement portion includes an upper rotation shaft extending in the vertical direction; The upper rotation shaft may penetrate and may have an upper bearing shorter than the upper rotation shaft.

  According to the present invention, for example, as compared with a chair provided with a hydraulic cylinder on the backrest, the waistline and the back of the seated person can be held with a simple configuration.

  In the chair according to the present invention, at least one of a rotatable area around the waist rotation axis, a rotatable area around the upper rotation axis, and a vertically movable area of the upper rotation axis is restricted. The configuration may further include a regulating unit. By providing the restricting portion, the degree of the hold can be adjusted according to the seated person.

  Further, at least one of the engagement portion of the waist portion and the engagement portion of the upper portion may be made of an elastic member. According to the present invention, the engagement portion of the waist portion and the engagement portion of the upper portion can be integrally formed, and the components are compared with the configuration including the waist portion rotational shaft and the waist portion bearing and the upper portion rotational shaft and the upper bearing. The score can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the technique regarding the chair which can hold a seated person's back and a waist can be provided irrespective of a seated person's attitude | position.

FIG. 1 shows an overall perspective view of the chair according to the first embodiment as viewed from the front side. FIG. 2 shows an overall perspective view of the chair according to the first embodiment as viewed from the back side. FIG. 3 shows an enlarged view of the engaging portion of the waist according to the first embodiment. FIG. 4 is an exploded perspective view of the engaging portion of the waist according to the first embodiment. FIG. 5 shows an enlarged view of the upper engaging portion according to the first embodiment. FIG. 6 is an exploded perspective view of the upper engaging portion according to the first embodiment. FIG. 7: shows the top view of operation | movement description of the engaging part of the waist part which concerns on 1st Embodiment at the time of load being uniformly applied to the back side. FIG. 8 shows a plan view of an operation explanation of the upper engaging portion according to the first embodiment when a load is applied to the back side evenly. FIG. 9 is a plan view of the operation of the engaging portion of the waist according to the first embodiment when a load is biased on the back side. FIG. 10 is a plan view of the operation of the upper engaging portion according to the first embodiment when a load is biased on the back side. FIG. 11 is an overall perspective view of the chair according to the second embodiment as viewed from the back side. FIG. 12 shows an enlarged view of the upper engaging portion according to the second embodiment. FIG. 13 shows an enlarged view of the engaging portion of the waist according to the first modification. FIG. 14 shows an enlarged view of the upper engaging portion according to the second modification. FIG. 15 shows an enlarged view of an engagement portion of a waist according to a third modification. FIG. 16 is an enlarged view of the engaging portion of the waist according to the fourth modification.

  Next, an embodiment of a chair according to the present invention will be described based on the drawings. Note that the embodiments described below are examples for carrying out the present invention, and the present invention is not limited to the embodiments described below.

First Embodiment
<< Configuration >>
As shown in FIGS. 1 and 2, the chair 1 according to the first embodiment includes the legs 2, the shaft member 3, the pedestal 4, the seat 5, the back plate 6, the backrest frame 7, and the engaging portion 8 (the waist portion Engaging portion 81, upper engaging portion 82).

  The legs 2 support the seat 5 and the back plate 6. The leg 2 consists of five legs arranged radially, and a caster is connected to the tip. Leg 2 concerning a 1st embodiment is an example, and can use an existing leg suitably. At the center of the leg 2, a shaft member 3 extending in the vertical direction is connected.

  The shaft member 3 supports the seat 5 and the back plate 6 together with the leg 2. The shaft member 3 is constituted by a hydraulic cylinder, and by operating a lever 9 provided on the side surface of the pedestal 4, the length can be adjusted to adjust the height position of the seat 5. The shaft member 3 may be configured by, for example, a rod-like member such as a pipe in order to make the configuration simpler. The lower end of the shaft member 3 is connected to the leg 2, and the upper end is connected to a pedestal 4 for supporting the seat 5.

  The seat 5 supports the buttocks of the seated person. The seat 5 is rectangular in plan view, and has a sufficient area to support the buttocks of the seat occupant. The seat 5 may have other shapes such as a circle and a trapezoid. In the first embodiment, the upper surface of the seat 5 is covered with a cover of the seat. A back plate 6 is provided at the end of the back side (rear) of the seat body 5.

The back plate 6 is provided at the rear of the seat 5 and supports the waist and back of the seat occupant. The back plate 6 is a vertically-long rectangular shape in a rear view, and a region in contact with the waist of the seated person protrudes to the front side (the seated person). More specifically, the back plate 6 is slightly bent so that the front side protrudes along an imaginary horizontal line (indicated by a dotted line in FIG. 1) located in the vicinity of the seat occupant's waist. In the first embodiment, the imaginary horizontal line is located below the vertical center of the back plate 6. Further, the back plate 6 is made of resin so as to be bent by a load when a seated person is seated, and further has a mesh structure. The plurality of holes forming the mesh of the back plate 6 are rhombus elongated in the vertical direction, but the shape of the holes is not particularly limited, such as a rectangle elongated in the vertical direction. In addition, the back plate 6 may have another shape such as a square, a circle, or a trapezoid. A backrest frame 7 is connected to the back of the back plate 6.

  The backrest frame 7 is provided on the back side of the backboard 6 at a distance from the backboard 6 and supports the backboard 6 via the engagement portion 8. The backrest frame 7 is located rearward of both end portions in the width direction of the back plate 6, and is connected to the two vertical frames 71 extending in the vertical direction and the vertical frame 71 and extends in the horizontal direction to the horizontal frame 72 (upper stage horizontal frame 721, lower horizontal frame 723). The vertical frame 71 is designed in accordance with the shape of the back plate 6 and is bent so that the area in contact with the waist of the seated person protrudes to the front side (the seated person's side). The upper end horizontal frame 721 has a base end connected to each of the upper ends of the vertical frames 71, and a tip end extending inward. A space is formed between tip portions of the upper horizontal frame 721. At the base end of the upper horizontal frame 721, an upper engaging portion 82 is provided via an arm 821. The lower horizontal frame 723 connects the vertical frames 71 at the lower end portion of the vertical frame 71. In addition, the backrest frame 7 mentioned above is only an example, for example, you may provide a middle stage horizontal frame between the upper stage horizontal frame 721 and the lower stage horizontal frame 723. FIG.

  The engagement portion 8 has a waist engagement portion 81 and an upper engagement portion 82. The engagement portion 81 of the lumbar portion is provided on each of the two vertical frames 71 located at both ends of the back plate 6, and allows the back plate 6 and the backrest to allow deflection due to the load when the seated person is seated. Engage with the frame 7. The upper engaging portion 82 is provided at a height position corresponding to the upper horizontal frame 721 and is provided at the tip of the arm 821 extending inward from both ends of the back plate 6. In other words, the upper engagement portion 82 is provided inside the engagement portion 81 of the waist.

  Here, FIG. 3 shows an enlarged view of the engaging portion of the waist according to the first embodiment. Moreover, FIG. 4 shows the disassembled perspective view of the engaging part of the waist part which concerns on 1st Embodiment. The lumbar engagement portion 81 allows relative movement between the back plate 6 and the backrest frame 7 about the lumbar rotational axis extending in the vertical direction. More specifically, the engagement portion 81 of the waist is a rod-like waist rotation shaft 811 extending in the vertical direction, a back plate side waist bearing 812 through which the waist rotation shaft 811 penetrates, and a frame side waist through which the waist rotation shaft 811 penetrates. A bearing 813 and a spring member 814 are provided. The waist rotation shaft 811 is fitted in an annular groove formed in the vicinity of the pin 811a and both ends of the pin 811a, and is constituted by a C ring 811b for restricting the movement of the pin 811a. The back plate side waist bearing 812 is a plate-like second back plate side disposed in parallel with the plate-like first back plate side waist bearing 812 a and the first back plate side waist bearing 812 a at a distance. And a waist bearing 812b. The first back plate side waist bearing 812 a and the second back plate side waist bearing 812 b have their bases connected to one another, and each has a through hole 812 c of the back plate side waist bearing through which the waist rotation shaft 811 passes. It is provided. In a space between the first back plate side waist bearing 812a and the second back plate side waist bearing 812b, a spring member 814 formed of a torsion coil spring is accommodated. A bolt may be used instead of the pin 811a, and a nut may be used instead of the C ring 811b.

  When the back plate side waist bearing 812 and the frame side waist bearing 813 are pivoted around the waist rotation shaft 811 by the load when the seated person is seated, the spring member 814 is a back plate when the load is released. The side waist bearing 812 and the frame side waist bearing 813 are urged to return to the original state (normal state).

  The frame-side waist bearing 813 includes a plate-shaped first frame-side waist bearing 813a and a plate-shaped second frame-side waist bearing 813b disposed in parallel with the first frame-side waist bearing 813a at a distance. have. The first frame-side waist bearing 813a and the second frame-side waist bearing 813b have their bases connected to one another, and through-holes 813c of the frame-side waist bearing through which the waist rotation shaft 811 penetrates are provided. There is. A back plate side waist bearing 812 is accommodated in a space between the first frame side waist bearing 813a and the second frame side waist bearing 813b. The distance between the first frame-side waist bearing 813a and the second frame-side waist bearing 813b is such that the height of the back plate-side waist bearing 812 can be regulated so that the vertical movement of the back plate-side waist bearing 812 can be restricted. It is designed to be almost the same.

  Here, FIG. 5 shows an enlarged view of the upper engaging portion according to the first embodiment. FIG. 6 is an exploded perspective view of the upper engaging portion according to the first embodiment. As described above, the upper engaging portion 82 is provided at the height position corresponding to the upper horizontal frame 721, and is provided at the tip of the arm 821 extending inward from the both ends of the back plate 6. The upper engagement portion 82 allows movement of the backrest frame 7 about the upper rotation axis extending in the vertical direction. More specifically, the upper engaging portion 82 includes a bar-shaped upper rotating shaft 821 extending in the vertical direction, a back plate upper bearing 822 through which the upper rotating shaft 821 passes, and a frame upper portion through which the upper rotating shaft 821 passes. And a bearing 823. The upper rotation shaft 821 is fitted with an annular groove formed in the vicinity of the pin 821a and both ends of the pin 821a, and is constituted by a C ring 821b for restricting the movement of the pin 821a. The back plate side upper bearing 822 is made of a plate-like member which is thicker than, for example, the plate-like first back plate side waist bearing 812a, and the through hole 822c of the back plate side upper bearing through which the upper rotation shaft 821 passes. Is provided. A bolt may be used in place of the pin 821a, and a nut may be used in place of the C ring 821b.

  The frame-side upper bearing 823 includes a plate-shaped first frame-side upper bearing 823a and a plate-shaped second frame-side upper bearing 823b disposed in parallel with the first frame-side upper bearing 823a with a space. have. The first frame-side upper bearing 823a and the second frame-side upper bearing 823b have their base portions connected, and through-holes 823c of the frame-side upper bearing through which the upper rotary shaft 821 penetrates are respectively provided. There is. A back plate side upper bearing 822 is accommodated in a space between the first frame side upper bearing 823a and the second frame side upper bearing 823b. The distance between the first frame-side upper bearing 823 a and the second frame-side upper bearing 823 b is such that the height of the back plate-side upper bearing 822 can be regulated so that the vertical movement of the back plate-side upper bearing 822 can be restricted. It is designed to be almost the same. A spring member may be provided as with the engagement portion 81 of the waist.

<< Operation >>
<< Left and right uniform load >>
FIG. 7: shows the top view of operation | movement description of the engaging part of the waist part which concerns on 1st Embodiment at the time of load being uniformly applied to the back side. FIG. 8 shows a plan view of an operation explanation of the upper engaging portion according to the first embodiment when a load is applied to the back side evenly. In the following description, left and right refer to a state in which a seated person is seated. That is, the left hand side of the seated person is described as the left, and the right side of the seated person is described as the right. Moreover, in FIG. 7, FIG. 8, the solid line which the code | symbol 6 points out shows the state of the back board 6 before a load acts, and the dotted line which the code | symbol 6 points shows the state of the back board 6 after a load acts. When a seated person is seated and is inclined rearward with uniform left and right loads, a load in the back direction acts on the back plate 6, and the back plate 6 begins to bend so that the back side expands.

As shown in FIG. 7, in the engagement portion 81 of the waist portion, a clockwise force acts on the engagement portion 81 of the left waist portion, and a counterclockwise force acts on the engagement portion 81 of the right waist portion. Do. As a result, the back plate 6 bends so that the back side bulges, with the waist of the seated person always in contact with the waist of the back plate 6. On the other hand, when the seated person takes a forward inclined posture with uniform left and right load, the load in the back direction acting on the back plate 6 is released, so the spring member 814 (see FIG. In 7, the biasing force of not shown acts, and the back plate 6 returns to the state before bending (normal state). The back plate 6 returns to the normal state in a state where the waist of the seated person is always in contact with the waist of the back plate 6 by the restoring force of the back plate and the biasing force of the spring member 814.

  Further, as shown in FIG. 8, the upper engaging portion 82 is positioned inside the both ends of the back plate 6, and the upper engaging portion 82 is loaded on the outside of the upper engaging portion 82. In the left upper engaging portion 82, a counterclockwise force acts, and in the right upper engaging portion 82, a clockwise force acts. As a result, the back plate 6 bends with the back of the seated person always in contact with the back plate 6. On the other hand, when the seated person takes a forward inclined posture with uniform left and right load, the load in the back direction acting on the back plate 6 is released, so the restoring force of the back plate 6 and the engagement portion 81 of the lumbar region The biasing force of the spring member 814 acts, and the back plate 6 returns to the state before the bending (normal state). The back plate 6 returns to the normal state with the back of the seated person always in contact with the back plate 6 by the restoring force of the back plate and the biasing force of the spring member 814.

<< Uneven load >>
FIG. 9 is a plan view of an operation explanatory view of the engaging portion of the waist according to the first embodiment when a load is biased on the back side. FIG. 10 is a plan view of the operation of the upper engaging portion according to the first embodiment when a load is biased on the back side. When a seated person is seated and takes a backward inclined posture with a load biased to the left, a load in the back direction acts on the back plate 6 and the back plate 6 starts to bend.

  In the case of a biased load, basically the same operation as the left-right uniform load is performed for the engagement portion 81 of the waist. That is, as shown in FIG. 9, a clockwise force acts on the engagement portion 81 of the left waist, and a counterclockwise force acts on the engagement portion 81 of the right waist. As a result, the back plate 6 bends so that the back side bulges, with the waist of the seated person always in contact with the waist of the back plate 6. On the other hand, when the seated person leans forward, the load in the back direction acting on the back plate 6 is released, so that the spring member 814 (shown in FIG. 9) is added to the restoring force of the back plate 6. The back plate 6 returns to the state before bending (normal state). The back plate 6 returns to the normal state in a state where the waist of the seated person is always in contact with the waist of the back plate 6 by the restoring force of the back plate and the biasing force of the spring member 814.

  On the other hand, regarding the upper engaging portion 82, a counterclockwise force acts on the upper upper engaging portion 82 also in the case of a unbalanced load. In addition, a clockwise force acts on the upper engaging portion 82 on the right side. However, since a larger load acts on the left side than on the right side, in particular, the left side of the back plate 6 is deformed to a greater degree so as to follow the seater's back. On the other hand, when the seated person takes a forward lean position, the load acting on the back plate 6 is released, so the restoring force of the back plate 6 and the biasing force of the spring member 814 of the engagement portion 81 of the waist act. The back plate 6 returns to the state before bending (normal state). The back plate 6 returns to the normal state with the back of the seated person always in contact with the back plate 6 by the restoring force of the back plate and the biasing force of the spring member 814.

<< Effect >>
In the chair 1 according to the first embodiment described above, the relative movement between the back plate 6 and the backrest frame 7 is allowed around the waist rotation shaft 811 extending in the vertical direction by providing the engagement portion 81 of the waist. Be done. Therefore, the waist portion of the back plate 6 is flexibly flexed, and the back plate 6 easily comes into contact with the seated person's waist. As described above, for example, even when the seated person takes forward and backward leaning postures with uniform left and right loads, the back plate 6 follows the waist of the seated person and the back plate 6 easily comes into contact with the seated person's waist Therefore, it is possible to always hold the seated person's waist area in particular. Further, in the chair 1 according to the first embodiment, by providing the upper engaging portion 82, the back plate 6 follows the back of the seated person even if the posture is changed as in the case of the waist, and the back plate 6 Since it becomes easy to hit the seater's back, the seater's back can always be held.

  For example, when the seated person takes a twisting posture (for example, a posture in which a large amount of load is applied to one side) or the like, it is assumed that the amount of displacement of the back above the waist, in other words, the back near the head, increases. Be done. In the chair 1 according to the first embodiment, the engagement portion 82 at the upper portion allows the back plate 6 to follow the movement of the back where the amount of displacement is assumed to be larger than that of the waist when the seated person changes the posture. Are located inward from both ends in the width direction of the back plate 6. Therefore, the back plate 6 can be deformed to the outside of the upper engaging portion 82. That is, in the chair 1 according to the first embodiment, the freedom of deformation of the back plate 6, in other words, the followability of the back plate 6 is improved as compared with the conventional case. Therefore, regardless of the posture of the seated person, it is possible to always hold the seated person's back and waist.

Second Embodiment
FIG. 11 shows an overall perspective view of a chair 1 'according to the second embodiment as viewed from the back side. FIG. 12 shows an enlarged view of the upper engaging portion 82 'according to the second embodiment. The upper engaging portion 82 'according to the second embodiment is configured so as to allow movement of the backrest frame 7 around the upper rotation axis extending in the vertical direction and in the vertical direction. It is different from the form. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is omitted.

  In the upper engaging portion 82 ′ according to the second embodiment, the distance between the first frame side upper bearing 823 a and the second frame side upper bearing 823 b is the distance between the back plate side upper bearing 822 in the vertical direction. In order to allow movement, it is designed to be longer than the height of the back plate side upper bearing 822. Thereby, the movement of the backrest frame 7 can be permitted not only around the upper rotation axis extending in the vertical direction but also in the vertical direction.

  As described above, in the chair 1 'according to the second embodiment, the engagement portion 82' at the upper portion allows the movement of the backrest frame 7 not only around the upper rotation shaft 821 extending in the vertical direction but also in the vertical direction. . Therefore, in the chair 1 'according to the second embodiment, the degree of freedom of deformation of the back plate 6, that is, the followability of the back plate 6 is further improved as compared with the chair 1' according to the first embodiment. Further, in the chair 1 ′ according to the second embodiment, as in the chair 1 according to the first embodiment, a space is formed between the tip portions of the upper horizontal frame 721. The upper engaging portion 82 'is configured to allow movement of the backrest frame 7 also in the vertical direction, so that the upper end portions of the two vertical frames 71 are deformed independently of each other according to the load. It also becomes possible. As a result, the freedom of deformation of the back plate 6 is further improved, and the back and waist of the seated person can be held more reliably regardless of the seated person's posture.

First Modified Example
FIG. 13 shows an enlarged view of the engaging portion of the waist according to the first modification. In the first embodiment described above, the engagement portion 81 of the waist according to the first modification further includes the waist regulation portion 10 for regulating the relative movement of the back plate 6 and the backrest frame 7. The structure is different from that of the engaging portion 81 of the lumbar. The restraining portion 10 of the lumbar portion has a projecting portion 814 which protrudes laterally from the base of the frame-side lumbar bearing 813, and the projecting portion 814 is a regulation in which a screw member 815 having a knob formed on its head is engaged. Part holes 814a are formed. The tip of the screw member 815 screwed into the hole 814 a of the restricting portion points to the back plate side waist bearing 812. When the screw member 815 is tightened, the tip of the screw member 815 contacts the back plate side waist bearing 812. Thereby, the relative movement between the back plate 6 and the backrest frame 7 can be restricted. In addition, by adjusting the degree of tightening, it is possible to adjust the movement range of movement relative to the back plate 6 and the backrest frame 7, which rotates around the waist rotation shaft 811.

Second Modified Example
FIG. 14 shows an enlarged view of the upper engaging portion according to the second modification. The upper engaging portion 82 'according to the second modification further includes the upper restricting portion 11 for restricting the upward and downward movement of the backrest frame 7. Therefore, the upper engaging portion 82' according to the second embodiment described above The configuration is different from that of the section 82 '. The upper regulation portion 11 is formed of a cylindrical member through which the upper rotation shaft 821 passes. The upper regulation portion 11 formed of a tubular member includes a part for filling a gap formed between the first frame upper bearing 823a and the back plate upper bearing 822; a second frame upper bearing 823b; And a part that fills the gap formed between the plate-side upper bearing 822 and the plate-side upper bearing 822. Thereby, the relative movement between the backboard 6 and the backrest frame 7 in the vertical direction can be restricted. In addition, the moving range of relative movement between the back plate 6 and the backrest frame 7 is adjusted by shortening the height of the upper regulation portion or by configuring the upper regulation portion 11 with only one part. be able to.

Third Modified Example
FIG. 15 shows an enlarged view of an engagement portion of a waist according to a third modification. The engagement portion 81a of the waist according to the third modification is made of an elastic material having a T-shaped cross section. The engagement portion 81a of the waist according to the third modification can be made of, for example, a rubber-based elastic material. By forming the engagement portion 81a of the waist with an elastic material, the movement of the backrest frame 7 is permitted by the deformation of the elastic material. As a result, the waist of the back plate 6 is flexibly flexed, and the waist of the seated person can always be held, as in the case of the chair 1 according to the first embodiment described above. In addition, the engaging part 81a of the waist part which concerns on a 3rd modification is applicable to the engaging part of an upper part. Thus, regardless of the posture of the seated person, it is possible to always hold the seated person's back and waist.

  FIG. 16 is an enlarged view of the engaging portion of the waist according to the fourth modification. The engagement portion 81b of the waist according to the fourth modification is continuous with both ends of the U-shaped curved portion 81b1 and the deformable U-shaped curved portion 81b1, and is connected to each of the back plate 6 and the backrest frame 7 It has connection part 81b2. The engagement portion 81b of the waist according to the fourth modification can be made of, for example, a resin-based material. The relative movement between the back plate 6 and the backrest frame 7 is permitted by being made of a resin-based material and including the deformable U-shaped curved portion 81b1. As a result, the waist of the back plate 6 is flexibly flexed, and the waist of the seated person can always be held, as in the case of the chair 1 according to the first embodiment described above. The engagement portion 81b of the waist according to the fourth modification can be applied to the upper engagement portion. Thus, regardless of the posture of the seated person, it is possible to always hold the seated person's back and waist.

  Although the preferred embodiments of the present invention have been described above, the chair according to the present invention is not limited thereto, and may include a combination of these as much as possible.

DESCRIPTION OF SYMBOLS 1 ... Chair 2 ... Leg 3 ... Shaft member 4 ... Receiving stand 5 ... Seat body 6 ... Back plate 7 ... Backrest frame 8 ... Engagement part 81 .. · Engaging portion 82 at the waist ··· Upper engaging portion

Claims (6)

The seat,
A back plate provided behind the seat body and flexed by a load when seated;
A backrest frame located behind the backboard and supporting the backboard;
An engagement portion connected to the backrest frame and engaging the backplate with the backrest frame so as to allow deflection of the backplate due to a load when seated;
The engagement portion is located near the waist of the seat occupant's waist and near both end portions in the width direction of the back plate, and the relative position between the back plate and the backrest frame about a waist rotation shaft extending vertically. Engaging portion of the waist that allows the movement, and above the engaging portion of the waist and inside the both end portions in the width direction of the back plate, and the waist portion in the width direction of the back plate A chair having an upper engaging portion which allows relative movement between the back plate and the backrest frame around an upper rotation axis which is located inward of the engaging portion and which extends in the vertical direction.   The chair according to claim 1, wherein the upper engagement portion allows relative movement between the back plate and the backrest frame around the upper rotation axis and in the vertical direction.   At least one of the engagement portion of the waist portion and the engagement portion of the upper portion has a biasing portion configured to bias the back plate bent by a load when seated. Or the chair as described in 2. The engagement portion of the waist has a waist rotation shaft extending in the vertical direction, and a waist bearing through which the waist rotation shaft passes.
The upper engaging portion includes an upper rotating shaft extending in the vertical direction, and an upper bearing through which the upper rotating shaft passes and which is shorter than the upper rotating shaft. The chair described in.   The control device according to claim 1, further comprising: a restricting portion configured to restrict at least one of a rotatable area around the waist rotational axis, a rotatable area around the upper rotational axis, and a vertically movable area of the upper rotational axis. A chair according to any one of 4. The chair according to claim 1, wherein at least one of the engagement portion of the waist and the engagement portion of the upper portion is made of an elastic member.

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